Purpose: The research problem of this article is to identify the elements of the post-transaction phase of logistics customer service in companies providing transport services with reference to the size of these entities, as well as examining the impact of selected post-transaction elements of logistics customer service on the faultlessness of the services of the surveyed companies. Design/Methodology/Approach: The questionnaire research made it possible to identify the elements of the post-transaction phase of logistics customer service practiced in the entities, with particular emphasis on the methods of after sales communication. The statistical analysis aimed to achieve the objective of this paper consisted in revealing the relation of post-transaction phase elements and size of the entities. This relationship was indicated by determining the correlation and testing statistical significance. The impact of selected post-transaction elements of logistics customer service on the measure of faultlessness of services of the surveyed companies was also tested, using multiple discriminant analysis. Findings: On the basement on the fragmentary survey results it should be assessed that they are identifiable in the current operations of entities, although their scope is significantly limited. Practical Implications: The research results can be used by managers of transport enterprises to create their logistics customer service strategy. Originality/Value: It is an original research study combining a market research based on questionnaire and multiple discriminant analysis with interesting managerial conclusions.